Applies To:
  • CitectSCADA 6.1, 7.0
  • CitectHMI 6.1, 7.0
  • CitectFacilities 6.1, 7.0
  • CitectSCADA Batch 6.1, 7.0
  • CitectSCADA Pocket 6.1, 7.0
Summary:

How do I detect which IO server is the Active one for a particular I/O Device (or devices) at runtime.


Solution:
Some customers need to detect the active IO server at runtime to perform some activities such like data logging. With the introduction of ServerInfoEx () in 6.1, it is not hard to do so:

FUNCTION active_ioserver_detection_v2() 
STRING sLocalServerName 
    sLocalServerName = ServerInfoEx ( "Server" , 0 , "IOServer" , "my_cluster" ) ; 
    IF(IODeviceInfo("mydev" , 17) = sLocalServerName) THEN 
        Message("Server Information", "This is the active IO server", 64);
                //Place your code here 
    END
 END

NOTE: THE ARGUMENTS FOR ServerInfoEx ARE CASE SENSITIVE AT THE TIME OF WRITING.

Prior V6.1, some hard coding is needed:

FUNCTION active_ioserver_detection()
STRING sPrimary = "primaryioserver" ; //primary IO server name
 STRING sStandby = "standbyioserver" ; //standby IO server name
 STRING sLocalPCName;
 STRING sLocalServerName; 

    sLocalPCName = ServerInfo ( "client" , 0 ) ; // get the IO server's computer name 
    IF(sLocalPCName = "SYD-D-XXXX") THEN //This part of the Cicode 
        sLocalServerName = sPrimary;     //maps the computer name 
    ELSE                                 //to IO server names 
        sLocalServerName = sStandby;     // 
    END                                  //

    IF(IODeviceInfo("mydev", 17) = sLocalServerName) THEN
        Message ( "Server Information" , "This is the active IO server" , 64 ) ; //Place your code here 
    END
 END

 
Keywords: